2021 ER4 is a very small asteroid whose orbit could bring it in close proximity to Earth. NASA JPL has classified 2021 ER4 as a "Near Earth Asteroid" due to its orbit's proximity to Earth, but it is not considered potentially hazardous because computer simulations have not indicated any imminent likelihood of future collision.
2021 ER4 orbits the sun every 293 days (0.80 years), coming as close as 0.47 AU and reaching as far as 1.26 AU from the sun. Based on its brightness and the way it reflects light, 2021 ER4 is probably between 0.010 to 0.022 kilometers in diameter, making it a small to average asteroid, very roughly comparable in size to a school bus or smaller.
2021 ER4's orbit is 0.00 AU from Earth's orbit at its closest point. This means that its orbit is relatively close to Earth's orbit.
2021 ER4 has 13 close approaches predicted in the coming decades:
| Date | Distance from Earth (km) | Velocity (km/s) |
|---|---|---|
| March 11, 2021 | 558,063 | 12.943 |
| March 12, 2025 | 10,690,648 | 14.982 |
| June 10, 2026 | 20,312,165 | 16.853 |
| March 14, 2029 | 21,916,429 | 17.346 |
| June 12, 2030 | 10,858,802 | 14.737 |
| March 16, 2033 | 28,493,102 | 18.717 |
| June 12, 2034 | 6,914,503 | 13.754 |
| June 13, 2038 | 5,521,421 | 13.217 |
| June 13, 2042 | 5,146,378 | 12.705 |
| June 13, 2046 | 7,273,487 | 11.819 |
| June 12, 2050 | 12,314,971 | 10.779 |
| March 12, 2098 | 5,659,558 | 11.719 |
| March 13, 2102 | 779,363 | 12.987 |
NASA Sentry has assessed impact risk for 1 very close approach scenarios. Here are the top scenarios ordered by probability of impact:
| Date | Probability of Impact (%) | Impact Energy (Mt) |
|---|---|---|
| March 13, 2119 | 0.00006 | 0.09483 |
2021 ER4's orbit is determined by observations dating back to March 15, 2021. It was last officially observed on March 18, 2021. The IAU Minor Planet Center records 19 observations used to determine its orbit.
The position of 2021 ER4 is indicated by a ◯ pink circle. Note that the object may not be in your current field of view. Use the controls below to adjust position, location, and time.